Conventional wireless peripheral communication protocols typically do not support encryption. Wireless keyboard communication, for example, to a host device is generally done in the clear. Most wireless communication circuitry used in keyboard conductivity is not sophisticated enough to provide public key/private key encryption. Those wireless keyboards that do support encryption usually use a shared secret based encryption. For example, during manufacturing, the secret key is permanently installed into both the wireless keyboard and the wireless receiver. However, one of the disadvantages with such an approach is that the wireless keyboard cannot be replaced independently of the wireless receiver. Such is a particular problem if the wireless receiver is built into a computer. Alternatively, in another technique, one device transmits the secret in the clear to another device during a wireless “binding” process, which can happen in the field. However, in the clear transmission of the secret is not an acceptable solution for some applications that demand better protection.
Yet another technique for enabling encryption that is made available in some wireless keyboards, but is seldom used, is a mode where a computer may instruct a user to type some long alphanumeric sequence key into the keyboard with no visual feedback so that the key is not transmitted over the air. However, one problem with this technique is how unfriendly it is for the user.
Currently there are Bluetooth® wireless keyboards and wireless receivers that are able to perform encryption. Specifically, in order to perform the encryption, the Bluetooth® wireless keyboard and its corresponding wireless receiver are each usually implemented with a 32-bit processor. However, such a type of implementation is not cost effective and also results in poor battery life for the Bluetooth® wireless keyboard.